1. Field of This Invention
This invention relates to a process for the catalytic production of 2-substituted pyridines from the correspondingly substituted cyano compounds and acetylene using a cobalt catalyst.
2. Prior Art
It is known to produce 2-substituted pyridines from the corresponding carboxylic acid nitriles and acetylene in the presence of the catalyst cyclopentadienyl-triphenylphosphine-tetraphenyl cobaltacyclopentadiene or cyclopentadienyl-triphenylphosphine-cobalt diphenyl acetylene at yields of about 23 or 16 percent, respectively [Tetrahedron Letters No. 36, (1973) pp. 3383 and 3384].
Furthermore, methyl heptadienylcobalt-butadiene [Synthesis, (1974), p 575] and a number of other, partly simple cobalt compounds (U.S. Pat. No. 3,829,429) have been proposed as catalysts for these systems,
The catalysts proposed or used hithertofore, however, provide uneconomical processes because of insufficient conversions and yields, as well as because of complicated partly multi-step production methods or insufficient thermal stability of the catalysts.